CN103518268B - Light-emitting component - Google Patents

Abstract

A kind of light-emitting component of the high efficiency with 25% left and right is provided. Light-emitting component comprises the luminescent layer that comprises phosphorescence object, N-shaped main body and p-type main body, and luminescent layer is clipped in containing the N-shaped layer of N-shaped main body and containing between the p-type layer of p-type main body, and N-shaped main body and p-type main body can form exciplex in luminescent layer. Realizing 1200cd/m²The low driving voltage (2.6V) of brightness under, light-emitting component shows high luminous efficiency (power efficiency of 74.3lm/W, 24.5% external quantum efficiency, 19.3% energy efficiency).

Description

Light-emitting component

Technical field

The present invention relates to utilize organic electroluminescent (EL:Electroluminescence) phenomenonLight-emitting component (following, this light-emitting component is also referred to as organic EL).

Background technology

Organic EL is researched and developed energetically. In the basic structure of organic EL,The layer (following, also referred to as luminescent layer) that comprises photism organic compound is clipped between pair of electrodes.Owing to can realizing slim lightweight, can carrying out high-speed response and can realize direct current input signalThe characteristic of low voltage drive etc., organic EL is closed as follow-on flat panel displaying elementNote. In addition, use the display of this light-emitting component have excellent contrast and picture quality withAnd the feature of wide viewing angle. Moreover because organic EL is area source, application is therefore supposed toIn the light source of backlight and the illumination etc. of liquid crystal display.

The luminescence mechanism of organic EL is carrier injection type. In other words, by for being clipped inApplying of the voltage of the luminescent layer between electrode, from electronics and the hole-recombination of electrode injection, so thatLuminescent substance is excited, and in the time that this excitation state is got back to ground state utilizing emitted light. The kind of excitation state canCan there be two kinds: singlet excited and triplet excited state. In addition the singlet excited in light-emitting component,Be considered to 1:3 with the generation ratio statistically of triplet excited state.

Conventionally, the ground state of photism organic compound is singlet state. Therefore, from singlet excitedThe luminous fluorescence that is called as because this is luminous due to the electron transition between identical spin multiplicityAnd occur. On the other hand, from the luminous phosphorescence that is called as of triplet excited state, wherein different fromRevolve electron transition occurs between multiplet. At this, (be called below, at the compound of emitting fluorescenceFluorescent chemicals) in, conventionally, at room temperature do not observe phosphorescence, and can only observe fluorescence.Therefore, the ratio (=1:3) based on above-mentioned singlet excited and triplet excited state, comprises fluorescenceInternal quantum (photon generating and the carrier injecting in the light-emitting component of compoundRatio) be considered to have 25% theoretical limit.

On the other hand, in the time using the compound (hereinafter referred to as phosphorescent compound) of transmitting phosphorescence,Internal quantum can bring up to 100% in theory. In other words, with when use fluorescent chemicalsIn time, is compared, and can obtain high-luminous-efficiency. For the above reasons, high efficiency luminous in order to realizeElement, develops the light-emitting component that comprises phosphorescent compound in recent years energetically.

Due to its high phosphorus photo-quantum efficiency, as phosphorescent compound, there is iridium etc. as central metalOrganometallic complex receive publicity. For example,, in patent documentation 1, as phosphor material public affairsHave and there is the organometallic complex of iridium as central metal.

In the time using above-mentioned phosphorescent compound to form the luminescent layer of light-emitting component, in order to suppress phosphorescenceConcentration quenching in compound or the quencher being caused by T-T annihilation, often with this phosphorusThe mode that optical compounds is dispersed in the matrix of another kind of compound forms luminescent layer. At this, be used asThe compound of matrix is called as main body, and is dispersed in compound in matrix such as phosphorescent compound quiltBe called object.

For luminous as in this light-emitting component of object by phosphorescent compound, conventionally have severalBasic process, and below this basic process is described.

(1) situation that electronics and hole-recombination, guest molecule are excited in guest molecule is (straightConnect recombination process).

(1-1) in the time that the excitation state of guest molecule is triplet excited state, guest molecule transmitting phosphorescence.

(1-2) in the time that the excitation state of guest molecule is singlet excited, in singlet excitedGuest molecule passes through the intersystem crossing (intersystemcrossing) of triplet excited state and sends outRadiophosphorus light.

In other words, in the direct combination process in (1), as long as the intersystem crossing of guest molecule effectRate and phosphorescence quantum efficiency are high, just can obtain high-luminous-efficiency.

(2) electronics and hole-recombination and the feelings of host molecule in excitation state in host moleculeCondition (energy transfer process).

(2-1) be that the triple of triplet excited state and host molecule excite in the excitation state of host moleculeEnergy level (T1 energy level) is during higher than the T1 energy level of guest molecule, and excitation energy shifts from host moleculeTo guest molecule, guest molecule is in triplet excited state thus. In the guest molecule of triplet excited stateSon transmitting phosphorescence. Note, need to consider the triple excitation levels (T1 energy level) for host moleculeBackward energy shift. Thereby the T1 energy level of host molecule need to be than the T1 energy level of guest moleculeHigh.

(2-2) be that the S1 energy level of singlet excited and host molecule is high in the excitation state of host moleculeIn the time of the S1 of guest molecule energy level and T1 energy level, excitation energy is transferred to guest molecule from host moleculeSon, guest molecule is in singlet excited or triplet excited state thus. In the visitor of triplet excited stateBody molecular emission phosphorescence. In addition, pass through triplet excited state in the guest molecule of singlet excitedIntersystem crossing and launch phosphorescence.

In other words, in the energy transfer process in (2), not only triple excitation energy, Er QiezhuIt is significantly important that the substance excitation energy of body molecule is transferred to guest molecule efficiently.

In view of above-mentioned energy transfer process, the excitation energy of host molecule transfer to guest molecule itBefore, when host molecule itself is when inactivation occurring as light or heat emission excitation energy, luminousEfficiency Decreasing.

<energy transfer process>

Below, describe intermolecular energy transfer process in detail.

First,, as intermolecular energy transfer mechanism, following two mechanism have been advocated. Provide sharpSend out can molecule be called as host molecule, and the molecule of accepting excitation energy is called as guest molecule.

" Foster () mechanism (dipole-dipole interaction) "

Foster mechanism (also referred to as Foster resonance energy shift (resonanceEnergytransfer)) shift and do not need intermolecular direct contact for energy. By master, there is energy and shift in the covibration of the dipole between body molecule and guest molecule. Pass through dipoleThe covibration of vibration, host molecule is to guest molecule supplying energy, and host molecule is in base thusState, and guest molecule is in excitation state. Formula (1) illustrates the velocity constant k of Foster mechanism_h ^* _→g。

[formula (1)]

$k_{h^{*}\&RightArrow;g}=\frac{9000c^4{K}^2\mathrm{\&phi;}\ln 10}{{128\mathrm{\&pi;}}^5{n}^4{\mathrm{N\&tau;R}}^6}\&Integral;\frac{{f^{\text{'}}}_h\left(v\right){\mathrm{\&epsiv;}}_g\left(v\right)}{v^4}\mathrm{dv}...\left(1\right)$

In formula (1), ν represents the number that vibrates, f '_h(ν) represent host molecule by standardizationEmission spectrum (fluorescence spectrum from the energy of singlet excited shifts, from triplet excited statePhosphorescence spectrum during energy shifts), ε_g(ν) molar absorption coefficient of expression guest molecule, N tableShow Avogadro number, n represents the refractive index of medium, R represent host molecule and guest molecule itBetween intermolecular distance, τ represents the life-span (fluorescence lifetime or phosphorescent lifetime) of measured excitation state,C represents the light velocity, and φ represents that the luminous quantum efficiency of host molecule (shifts from the energy of singlet excitedIn fluorescence quantum efficiency, the phosphorescence quantum efficiency from the energy of triplet excited state shifts), K²Represent the coefficient (0 to 4) of the orientation of the transition dipole moment between host molecule and guest molecule.Note K in random orientation²=2/3。

" dexter (Dexter) mechanism (electron exchange interaction) "

(shift (Dexterelectron also referred to as dexter electronics in dexter mechanismTransfer)), host molecule and guest molecule are close to their the connecing of Orbital Overlap whereinTouch coverage, the host molecule in excitation state and the guest molecule in ground state exchange theirsElectronics, this causes that energy shifts. Formula (2) illustrates the velocity constant k of dexter mechanism_h ^* _→g。

[formula (2)]

$k_{h^{*}\&RightArrow;g}=\left(\frac{2\mathrm{\&pi;}}{h}\right)K^2\exp (-\frac{2R}{L})\&Integral;{f^{\text{'}}}_h\left(v\right){{\mathrm{\&epsiv;}}^{\text{'}}}_g\left(v\right)\mathrm{dv}...\left(2\right)$

In formula (2), h represents Planck's constant, and K represents to have energy dimension (energyDimension) constant, ν represents the number that vibrates, f '_h(ν) represent host molecule by standardizationEmission spectrum (fluorescence spectrum from the energy of singlet excited shifts, from triplet excited statePhosphorescence spectrum during energy shifts), ε '_g(ν) represent guest molecule by standardized absorption lightSpectrum, L represents effective molecular radius, R represents the intermolecular distance between host molecule and guest moleculeFrom.

At this, can think that formula (3) illustrates that the energy from host molecule to guest molecule shiftsEfficiency (energy transfer efficiency Φ_ET). In formula, k_rRepresent the luminescence process of host molecule(fluorescence the transfer of the energy from host molecule in singlet excited, in triplet excited stateThe energy from host molecule shift phosphorescence) velocity constant, k_nRepresent non-luminescence process (heatInactivation or intersystem crossing) velocity constant, and τ represents the excitation state of measured host moleculeLife-span.

[formula (3)]

${\mathrm{\&Phi;}}_{\mathrm{ET}}=\frac{k_{h^{*}\&RightArrow;g}}{k_r+k_n+k_{h^{*}\&RightArrow;g}}=\frac{k_{h^{*}\&RightArrow;g}}{\left(\frac{1}{\mathrm{\&tau;}}\right)+k_{h^{*}\&RightArrow;g}}...\left(3\right)$

First, known according to formula (3), by with the velocity constant k of other competitions_r+k_n（=1/τ）Compare the velocity constant k that further raising energy shifts_h ^* _→g, can improve energy transfer efficiency Φ_ET。And, for the velocity constant k of energization transfer_h ^* _→g, based on formula (1) and formula (2),In Foster mechanism and dexter mechanism, preferably, the emission spectrum of host molecule (fromFluorescence spectrum during the energy of singlet excited shifts, the phosphorus from the energy of triplet excited state shiftsLight spectrum) with the absorption spectrum of guest molecule (in the situation that of common phosphorescence, triplet excited stateAnd the energy difference between ground state) overlapping large.

[bibliography]

No. 2000/070655th, [patent documentation 1] PCT International Publication

Summary of the invention

As mentioned above, by using phosphorescent compound can obtain high efficiency light-emitting component. From energyAmount transfer process is known, in order to realize high efficiency light-emitting component, needs the utilizing emitted light of host moleculeSpectrum and the absorption spectrum of guest molecule large overlapping. Moreover, in order to suppress the T1 from guest moleculeEnergy level shifts to the backward energy of the T1 energy level of host molecule, and the T1 energy level of guest molecule needs ratioThe T1 energy level of guest molecule is high.

Generally speaking, be used as phosphorescent organometallic complexes (for example iridium cooperation of phosphorescence guest moleculeThing) in relative long wavelength region, there is the triplet of deriving from MLCT(metal-to-ligandChargetransfer: electric charge from metal to part shifts) absorption shifted. Its exciting lightNear the absorption of spectrum this long wavelength region of prompting (being mainly positioned at 450nm) contributes to guest molecule very muchLuminous. Therefore, preferably, the absorption of this long wavelength region and the phosphorescence spectrum of host moleculeOverlapping large. This is because following cause: due to this large overlapping, allow to produce efficiently from masterThe energy of the triplet excited state of body molecule shifts, and its result, generates the triple of guest molecule efficientlyExcitation state.

On the other hand, because the S1 energy level of host molecule is higher than T1 energy level, so than correspondenceIn the phosphorescence spectrum of T1 energy level, in shorter wavelength region, observe glimmering corresponding to S1 energy levelLight spectrum. This means the long wavelength region that appears at of the fluorescence spectrum of host molecule and guest moleculeThe overlapping minimizing of the absorption of (deriving from triplet MLCT shifts). Thus, can not be fully sharpUse from the singlet excited of host molecule and shift to the energy of guest molecule.

In other words, in existing phosphorescence light-emitting component, as extremely low in lower probability: from host moleculeSinglet excited shifts generation and generates because intersystem crossing is continuous to the energy of phosphorescence guest moleculeBe converted to the singlet excited of the guest molecule of triplet excited state.

The present invention provides in view of the above problems, and a mode of the present invention provide a kind of based onThe light-emitting component of new principle. In addition, a mode of the present invention provides one to have high outside quantumThe light-emitting component of efficiency.

A mode of the present invention is a kind of light-emitting component, and this light-emitting component comprises: pair of electrodes (theOne electrode and the second electrode) between comprise phosphorescent compound (object), the first organic compoundAnd the luminescent layer of the second organic compound; Comprising between luminescent layer and the first electrode first organisesCompound, and do not comprise the layer (ground floor) of the second organic compound; And luminescent layer and the second electricityBetween the utmost point, comprise the second organic compound, and do not comprise the layer (second of the first organic compoundLayer).

In above-mentioned light-emitting component, the first organic compound has the electronics biography that is better than hole transport abilityDefeated property, and the second organic compound has the hole transport ability that is better than electron-transporting. First hasOrganic compounds and the second organic compound form exciplex (exciplex) and (are excitedComplex) material. In said structure, shift through the energy from exciplex to objectAnd object is excited, and obtain luminous from the excitation state of object. Note, the layer beyond luminescent layer canWith the utilizing emitted light in response to electric current injects.

Can think that exciplex has between substance excitation energy and triple excitation energy littleCapacity volume variance. In other words, from the luminous of singlet excited and from triplet excited state luminous go outNow extremely near wavelength zone each other. In addition, due to general compared with free state exciplexLuminous observed in long wavelength's one side, appear at long wavelength region and derive from triple so can increaseOverlapping between the absorption of phosphorescent compound that state MLCT shifts and exciplex luminous. ThisMean that energy can transfer to efficiently from the both sides of the singlet state of exciplex and tripletPhosphorescent compound, this contributes to the raising of the efficiency of light-emitting component.

Moreover exciplex does not have ground state. Thereby, due to the triplet not having from guest moleculeArrive the process of the backward energy transfer of the exciplex of host molecule, so can ignore because of processThe reduction of the efficiency of the light-emitting component that this process causes.

In this manual, according to the electric transmission of the first organic compound and the second organic compoundThe feature of property or hole transport ability, the first organic compound and the second organic compound are also claimed respectivelyFor N-shaped main body, p-type main body. Either party in N-shaped main body and p-type main body can be also transmittingThe material of fluorescence. N-shaped main body in luminescent layer and the ratio of p-type main body are all preferably more than 10%.

N-shaped master also can be set between ground floor and luminescent layer or between the second layer and luminescent layerThe region that the ratio of body and p-type main body changes continuously. Note, the N-shaped main body in luminescent layer andThe ratio of p-type main body also can be set as changing continuously.

Other modes of the present invention are a kind of light-emitting components, and this light-emitting component comprises: comprise N-shaped masterThe N-shaped body layer of body; The p-type body layer that comprises p-type main body; And be positioned at N-shaped body layer andBetween p-type body layer and the region that comprises N-shaped main body, p-type main body and object. N-shaped main body and pType main body is the material that forms exciplex.

In above-mentioned light-emitting component, phosphorescent compound is preferably organometallic complex. Phosphorescence chemical combinationThing also preferably comprises iridium. Phosphorescent compound can also be included in ground floor, except luminescent layerTwo layers, region between the region between luminescent layer and ground floor or luminescent layer and the second layer.

In a mode of the present invention, luminescent layer comprises N-shaped host molecule, p-type host moleculeAnd guest molecule. Certainly, molecule, can be almost not regularly without the need for arranging regularly yetArrange. Especially,, when as thickness being film below 50nm while forming luminescent layer, preferably locateIn amorphous state, thus, the combination that is not easy the material of crystallization is preferred. In addition N-shaped main body,Layer or p-type body layer also can comprise plural different types of compound.

The light-emitting component of any mode of the present invention can be applied to light-emitting device, electronic equipment andLighting device.

In the time becoming excitation state, it is compound that suitable being combined to form of N-shaped main body and p-type main body swashs baseThing. Note, the necessary condition of the formation of exciplex is the HOMO energy level < p-type of N-shaped main bodyThe lumo energy of lumo energy < p-type main body of HOMO energy level < N-shaped main body of main body, but this is notIt is adequate condition. For example,, although Alq₃Meet above-mentioned condition with NPB, but it is compound not form sharp baseThing.

Be directed to this, in the situation that N-shaped main body and p-type main body can form exciplex,The singlet state from exciplex by as described above and triplet are to the energy of guest moleculeThe process that amount shifts, guest molecule can become and excites, thus with existing phosphorescence light-emitting component phaseThan improving luminous efficiency.

The joint that has different layers at light-emitting component, the energy gap that is created in interface causes drivingThe moving increase of voltage and the reduction of power efficiency (with reference to patent documentation 2). Therefore, preferably sending outIn optical element, reduce the number of the joint of different materials as far as possible.

In any of aforesaid way, the mixture that comprises N-shaped main body and p-type main body luminousInterface between layer and N-shaped body layer is as for the stopping of hole, but is used as for electricity hardlyThe obstacle of son. Interface between luminescent layer and p-type body layer is as for the stopping of electronics, but severalBe not used as the obstacle for hole. Thus, electronics and hole are enclosed in luminescent layer or at N-shapedBetween body layer and p-type body layer. Consequently, can prevent that electronics and hole from just arriving respectivelyThe utmost point and negative pole, therefore can improve luminous efficiency. Generally speaking, exciplex provides wide sending outPenetrate spectrum. On the other hand, because guest molecule in a mode of the present invention is luminous, so canTo obtain half width less emission spectrum, can realize thus launching and there is good colorThe formation of the light-emitting component of the light of purity.

[bibliography]

No. 7572522 description of [patent documentation 2] United States Patent (USP)

Brief description of the drawings

Figure 1A to Fig. 1 I is concept map of the present invention;

Fig. 2 A to Fig. 2 D illustrates principle of the present invention;

The example of Fig. 3 A to Fig. 3 E explanation embodiments of the present invention;

The example of Fig. 4 A to Fig. 4 C explanation embodiments of the present invention;

The example of Fig. 5 A and Fig. 5 B explanation embodiments of the present invention;

Fig. 6 A and Fig. 6 B illustrate the example of embodiments of the present invention;

Fig. 7 A to Fig. 7 C is illustrated in the characteristic of the light-emitting component obtaining in embodiment 1;

Fig. 8 A to Fig. 8 C is illustrated in the characteristic of the light-emitting component obtaining in embodiment 2.

Detailed description of the invention

With reference to accompanying drawing, embodiment is elaborated. Note, the present invention is not limited to following theoryBright, be exactly it and person of an ordinary skill in the technical field can understand a fact easilyMode and detailed content can be transformed in the situation that not departing from aim of the present invention and scope thereofFor various forms. Therefore, the present invention should not be interpreted as being only confined to shown belowIn the content that embodiment is recorded. Note, in the structure of the following invention illustrating, in differenceAccompanying drawing between jointly represent identical part or there is identical merit with identical Reference numeralThe part of energy, and omit its repeat specification.

Embodiment 1

As shown in Figure 1A, the light-emitting component 101a of present embodiment example comprises bagContaining the N-shaped body layer 103 of N-shaped main body, the p-type body layer 104 that comprises p-type main body and folderBetween these layers and the both sides that comprise N-shaped main body and p-type main body layer (hereinafter referred to as luminescent layer102). In luminescent layer 102, be dispersed with guest molecule 105.

Figure 1B illustrates that the concentration of the N-shaped main body in light-emitting component 101a is (in the accompanying drawings with " N "Represent) and the distribution of the concentration (representing with " P " in the accompanying drawings) of p-type main body. In luminous unitThe concentration of the N-shaped main body in the luminescent layer 102 in part 101a is 80%, the concentration of p-type main bodyBe 20%. In other words,, in luminescent layer 102, the ratio of N-shaped main body and p-type main body is 4:1.This ratio can consider transmission characteristic of N-shaped main body and p-type main body etc. and determine, but preferably luminousN-shaped main body in layer and the concentration of p-type main body are all more than 10%.

As shown in Figure 1 C, guest molecule 105 is dispersed in luminescent layer 102, but the present inventionBe not limited to this. Guest molecule 105 also can be dispersed in a part or the p of N-shaped body layer 103In a part for type body layer 104. Note, in the accompanying drawings, " G " represents the dense of guest moleculeDegree distributes.

In N-shaped body layer 103, the concentration of p-type main body is extremely low, and below 0.1%, andIn p-type body layer 104, the concentration of N-shaped main body is extremely low, and below 0.1%. Certainly,Interface between luminescent layer 102 and N-shaped body layer 103 and in luminescent layer 102 and p-type main bodyThe change in concentration at the interface between layer 104 not necessarily needs sharply to change.

Fig. 1 D illustrates the example of other light-emitting components 101b of present embodiment. Light-emitting component 101bComprise the N-shaped body layer 103 identical with light-emitting component 101a, p-type body layer 104, luminescent layer102. And, in luminescent layer 102, be dispersed with guest molecule 105.

With light-emitting component 101a difference be luminescent layer 102 and N-shaped body layer 103 itBetween be provided with the region that the concentration of N-shaped main body and the concentration of p-type main body changes lentamente (following,Be called N-shaped transition region 106), and be provided with between luminescent layer 102 and p-type body layer 104The region that the concentration of the concentration of N-shaped main body and p-type main body changes lentamente (is called p-type below,Transition region 107).

Note, light-emitting component 101b not necessarily must comprise N-shaped transition region 106 and p-type mistakeCross district 107 these two. In some cases, N-shaped transition region 106 and p-type transition region 107 toolsThere is lighting function. Thereby in a broad sense, N-shaped transition region 106 and p-type transition region 107 also canTo be considered as luminescent layer. In the case, luminescent layer 102 also can be considered as main luminescent layer. N-shapedThickness more than transition region 106 and p-type transition region 107 can have 1nm and below 50nm.

Fig. 1 E illustrates the CONCENTRATION DISTRIBUTION of N-shaped main body and p-type main body, at N-shaped transition region 106 and pIn type transition region 107, the concentration of N-shaped main body and p-type main body changes continuously. In addition, as figureShown in 1F, guest molecule 105 can be to be not only included in luminescent layer 102 but also to be included inMode in N-shaped transition region 106 and p-type transition region 107 arranges, moreover, also can be to compriseMode in a part for N-shaped body layer 103 and p-type body layer 104 arranges. Certainly, alsoGuest molecule 105 can be only set in luminescent layer 102.

Fig. 1 G illustrates other light-emitting components 101c of present embodiment. In light-emitting component 101c asShown in Fig. 1 H, be clipped in n in the region between N-shaped body layer 103 and p-type body layer 104The concentration of the concentration of type main body and p-type main body changes continuously. In the case, light-emitting componentLuminescent layer (or main luminescent layer) in 101a and light-emitting component 101b is difficult to definition, but nType main body and p-type main body concentration mixed and N-shaped main body and p-type main body is all more than 10%Region can be considered luminescent layer in a broad sense.

As shown in Figure 1 I, can set visitor in the mode being included in sensu lato luminescent layerThe concentration of body. Note, in Figure 1A to Fig. 1 I, p-type body layer 104 clips luminescent layer 102Be arranged on N-shaped body layer 103. But, for the purpose of convenience, providing said structure, can hold very muchChange places understand the following fact be exactly antistructure be that N-shaped body layer 103 is arranged on p-type body layer 104On structure be also included within mode of the present invention.

The energy level of above-mentioned light-emitting component 101a is described with reference to Fig. 2 A. As described above, N-shaped masterHOMO energy level and the lumo energy of body, p-type main body have following relation: the HOMO energy of N-shaped main bodyThe lumo energy of lumo energy < p-type main body of HOMO energy level < N-shaped main body of level < p-type main body.

On the other hand, being mixed with in the luminescent layer 102 of N-shaped main body and p-type main body, due to skyCave and electronics utilize respectively the HOMO energy level of p-type main body and the lumo energy of N-shaped main body to be transmitted,So the viewpoint shifting from carrier, can think that HOMO energy level is equal to p-type main bodyHOMO energy level, and lumo energy is equal to the lumo energy of N-shaped main body. Consequently, sending outInterface between photosphere 102 and p-type body layer 104 produces difference between lumo energy,This is as stopping of shifting for electronics. Similarly, at luminescent layer 102 and N-shaped body layer 103Between interface, between HOMO energy level, produce difference, this as for hole shift stopping.

On the other hand, the interface between luminescent layer 102 and p-type body layer 104, HOMO energy levelEquate, that does not shift for hole thus stops, also at luminescent layer 102 and N-shaped body layer 103Between interface, lumo energy equates, that does not shift for electronics thus stopping.

Consequently, electronics is easily transferred to luminescent layer 102 from N-shaped body layer 103, but sends outDifference between the lumo energy of photosphere 102 and p-type body layer 104 hinders from luminescent layer 102Electronics to p-type body layer 104 shifts.

Similarly, luminescent layer 102 is easily transferred to from p-type body layer 104 in hole, but luminousDifference between layer 102 and the HOMO energy level of N-shaped body layer 103 hinders from luminescent layer 102 to nShift in the hole of type body layer 103. Consequently, electronics and hole can be enclosed in luminescent layer 102In.

The energy level of above-mentioned light-emitting component 101b is described with reference to Fig. 2 B. Although luminescent layer 102, N-shapedHOMO energy level and the lumo energy of body layer 103 and p-type body layer 104 are identical with Fig. 2 A,But need to pay close attention to N-shaped transition region 106 and p-type transition region 107. In these regions, N-shapedThe concentration of the concentration of main body and p-type main body changes continuously.

But, for example, with inorganic semiconductor material (, Ga_xIn_1-xN(0 < x < 1)) conduction band andValence band is along with the situation difference that changes continuously of variation of composition, is mixed with organic compoundsLumo energy and HOMO energy level almost do not change continuously. This is leading because of organic compoundElectricity is the edge of the hopping conduction (hoppingconduction) different from the conduction of inorganic semiconductorTherefore.

For example, in the time of the concentration reduction of N-shaped main body and the concentration rising of p-type main body, electronics is not allowedEasily conduction, this is interpreted as and is not because lumo energy rises continuously, but due to because of N-shaped masterThe increase of the distance between body molecule and the probability of the transfer that causes reduces, and due to needs forTo have higher N-shaped main body lumo energy adjacent p-type main body lumo energy jumpAdditional energy.

Therefore,, in N-shaped transition region 106, its HOMO is the HOMO of N-shaped main body and p-type main bodyAdmixture, specifically, in the part close to from luminescent layer 102, its HOMO is p-typeThe probability of the HOMO of main body is higher, and in the part close to more from N-shaped body layer 103 its HOMOFor the probability of the HOMO of N-shaped main body higher. In p-type transition region, be also same.

But, even if there is N-shaped transition region 106 as described above and p-type transition region 107, alsoInterface between luminescent layer 102 and p-type body layer 104 produces difference between lumo energy,This is used as stopping of shifting for electronics, and between luminescent layer 102 and N-shaped body layer 103Interface produces difference between HOMO energy level, and this is as stopping of shifting for hole. This and figure2A is identical.

Note, the interface sharply of change in concentration as shown in Figure 2 A causes because for example electronics is concentratedThe probability of staying this interface is compared with high and easily deteriorated problem of near interface. Be directed to this, due to electricityIn the part that son remains in probability and determines, so does not lead at fuzzy interface as shown in Figure 2 BCause the deteriorated of specific part. In other words, can relax the deteriorated of light-emitting component, can improve thusIts reliability.

On the other hand, the interface between luminescent layer 102 and p-type transition region 107 and in p-typeInterface between transition region 107 and p-type body layer 104, HOMO energy level equates, not right thusThat shifts in hole stops, and interface between luminescent layer 102 and N-shaped transition region 106 andInterface between N-shaped transition region 106 and N-shaped body layer 103, lumo energy is equal, thusThat does not shift for electronics stops.

Consequently, electronics is easily transferred to luminescent layer 102 from N-shaped body layer 103, but p-typeDifference between lumo energy in transition region 107 hinders from luminescent layer 102 to p-type body layer104 electronics shifts. Similarly, luminescent layer 102 is easily transferred to from p-type body layer 104 in hole,But hindering, the difference between the HOMO energy level in N-shaped transition region 106 transfers to n from luminescent layer 102Shift in the hole of type body layer 103.

Consequently, electronics and hole can be enclosed in luminescent layer 102. At N-shaped body layer 103And the concentration of the N-shaped main body between p-type body layer 104 and the concentration of p-type main body change continuouslyLight-emitting component 101c in, can similarly think, electronics and hole can be enclosed in n efficientlyBetween type body layer 103 and p-type body layer 104.

The excitation process of guest molecule 105 then, is described. At this, in explanation with light-emitting component101a is example; Light-emitting component 101b and light-emitting component 101c are too. As mentioned above, excitedJourney comprises direct combination process and energy transfer process.

Fig. 2 C explanation direct combination process, wherein electronics is from being connected in the N-shaped body layer 103 of negative poleBe injected into the LUMO of luminescent layer 102, and hole is injected from being connected in anodal p-type body layer 104To the HOMO of luminescent layer 102. Because guest molecule 105 is present in luminescent layer 102, soUnder suitable condition, inject electronics and hole, guest molecule by the LUMO to guest molecule and HOMOSon can be in excitation state (molecule exciton).

But, due to electronics and hole are injected into sparsely dispersion in luminescent layer 102 efficientlyThe LUMO of guest molecule and HOMO in be very difficult technically; Thus, this process is generalRate is enough not high. By with guest molecule preferentially the mode of trapped electron the LUMO of object is establishedBe decided to be the low 0.1eV to 0.3eV than the LUMO of N-shaped main body, can raise the efficiency. By by objectHOMO be set as also can obtaining same than the high 0.1eV to 0.3eV of the HOMO of p-type main bodyEffect. Note, in Fig. 2 C, the HOMO of object is lower than the HOMO of p-type main body. But,Because the LUMO of object is fully lower than the LUMO of N-shaped main body and p-type main body, so electronic high-effectiveBe captured.

Although the probability of capturing of electronics (hole) improves, the electric conductivity of luminescent layer 102 is fallenLow, and be only positioned at the guest molecule local excitation of negative pole one side (an anodal side), therefore by visitorThe LUMO of body is set as above (or by the HOMO of object than the low 0.5eV of the LUMO of N-shaped main bodyBe set as than more than the high 0.5eV of the HOMO of p-type main body) not preferred.

Fig. 2 D is that N-shaped main body and p-type main body are suitably selected in explanation according to the present invention, forms and swashsThe figure of the situation of base complex. Being injected in luminescent layer 102 with above-mentioned similarly electronics and holeSituation under, compare with the probability that electronics is encountered in guest molecule with hole, in luminescent layer 102N-shaped host molecule located adjacent one another and p-type host molecule in the probability encountered high. In this feelingsUnder condition, form exciplex. At this, describe exciplex in detail.

Exciplex forms by the interaction between the heterologous molecule in excitation state. ManyInstitute is known, and exciplex has the organic compound of relatively dark lumo energy (N-shaped main body)Easily form with having between the organic compound (p-type main body) of relative shallow HOMO energy level.

The emission wavelength of exciplex depends on respectively the HOMO energy of p-type main body and N-shaped main bodyEnergy difference between level and lumo energy. In the time that energy difference is large, emission wavelength is short. At energy differenceHour, emission wavelength is long. In the time forming exciplex by the molecule of N-shaped main body and p-type main body,The lumo energy of exciplex and HOMO energy level derive from respectively N-shaped main body and p-type main body.

Therefore, the energy difference of exciplex is than the energy of the energy difference of N-shaped main body and p-type main bodyPoor little. In other words, the emission wavelength of exciplex is than the luminous ripple of N-shaped main body and p-type main bodyLong.

The forming process of exciplex is considered to roughly be divided into two kinds of processes.

" electricity causes exciplex (Electroplex) "

In this manual, " electricity causes exciplex " refers to the N-shaped main body using in ground stateAnd the exciplex directly forming in the p-type main body of ground state. For example, electricity causes exciplexIt is the exciplex that uses the anion of N-shaped main body and the cation of p-type main body directly to form.

As mentioned above, in the energy transfer process in the luminescence process of traditional organic compound,Electronics and hole-recombination (cause and excite) in host molecule, excitation energy is from excitation stateHost molecule is transferred to guest molecule, and guest molecule is in excitation state thus, and luminous.

Now, before excitation energy is transferred to guest molecule from host molecule, host molecule itselfLuminous or excitation energy is converted to thermal energy, therefore causes the inactivation of excitation energy. Especially,At host molecule during in singlet excited, excite the life-span compared with situation in triplet excited stateShort, therefore easily cause the inactivation of excitation energy. The inactivation of excitation energy causes light-emitting componentOne of reason of the deteriorated and reduction in life-span.

But, there is N-shaped host molecule and the p of carrier (cation or anion) in useWhen type host molecule forms electricity and causes exciplex, can suppress to excite short singlet state exciton of life-spanFormation. In other words, may have under the state that does not form singlet state exciton and directly form and swashThe process of base complex. Thus, can also suppress the list of N-shaped host molecule or p-type host moleculeThe inactivation of heavy excitation energy. Thereby, can obtain long light-emitting component of life-span.

Like this, by suppress host molecule singlet excited generation and by energy from replaceThe electricity forming causes exciplex and transfers to guest molecule and obtain and have the luminous of high-luminous-efficiencyElement is new concept.

" formation of the exciplex by exciton "

As another process, consider N-shaped with in p-type host molecule one square become singlet stateAfter exciton, interact and the basic mistake of formation exciplex with the opposing party in ground stateJourney. To cause exciplex different from electricity, in the case, temporarily generate N-shaped host molecule or pThe singlet excited of type host molecule, compound but this singlet excited is promptly transformed to sharp baseThing, can suppress the inactivation of substance excitation energy thus. Thereby, can suppress exciting of host moleculeThe inactivation of energy.

Note the difference between N-shaped and the HOMO energy level of p-type main body and N-shaped and p-type masterWhen differing greatly between the lumo energy of body (particularly, more than 0.3eV), electronics is preferentialBe injected in N-shaped host molecule, and hole is preferentially injected in p-type host molecule. At thisIn situation, can think with form the process of exciplex through singlet state exciton compared with, preferentialForm the process that electricity causes exciplex.

Note, in the time considering the importance of the absorption that MLCT shifts, shift in order to improve energyThe efficiency of process, preferably in the arbitrary mechanism in above-mentioned Foster mechanism and dexter mechanism,With independent emission spectrum (or being equivalent to energy difference) and the object of N-shaped main body (or p-type main body)The overlapping of absorption spectrum compare, electricity causes the emission spectrum of exciplex and/or exciplexOverlapping large with the absorption spectrum of object.

In addition,, in order to improve energy transfer efficiency, preferably improve the concentration of object not cause concentrationThe degree of cancellation, and the weight ratio of the total amount of the concentration of object to N-shaped main body and p-type main body is 1%To 9%.

Note, no matter excitation process is direct combination process or energy transfer process, do not know in the past asLower concept, wherein causes sharp base by the exciplex from N-shaped and p-type main body and/or electricity compoundThe guest molecule that thing shifts in N-shaped and p-type main body to the energy of guest molecule excites. In this explanationIn book, this concept be called as " GuestCoupledwithComplementaryHosts " (GCCH:The coupling of object and complementary main body). By utilizing this concept, not only realize the envelope of carrier simultaneouslyClose and and reduced the shielding of the carrier injection to luminescent layer, but also can utilize from its substanceWith the both sides' of triplet excited state energy transfer process, can realize thus and there is low driving voltageThe formation of high efficiency light-emitting component (in other words, power efficiency is very high).

Embodiment 2

Fig. 3 A illustrates an example of the light-emitting device of present embodiment. Luminous dress shown in Fig. 3 APutting is illustrated luminous of for example embodiment 1 of the illustrated light-emitting component 101(of embodiment 1Element 101a, light-emitting component 101b or light-emitting component 101c) be clipped in negative pole 108 and anodal 109Between light-emitting device. Note, at least one party in negative pole 108 and anodal 109 is preferably transparent.This light-emitting device also can be arranged on suitable substrate.

In light-emitting component 101, clamp N-shaped body layer 103 and the p-type main body of luminescent layer 102Layer 104 is used separately as electron transfer layer and hole transmission layer, and, as mentioned above, be used separately asBlocking hole and electronics. Therefore, do not need to arrange separately and be equivalent to electron transfer layer and hole transportThe layer of layer. The manufacturing process of the light-emitting device shown in thus, can reduced graph 3A.

Light-emitting component 101 object, N-shaped main body and the p-type main body of comprising as illustrated in embodiment 1.Can use two or more materials as N-shaped main body (or p-type main body).

As object, organometallic complex is preferred, and especially, complex of iridium is preferred.Considering while shifting due to the energy of Foster mechanism, be positioned at the phosphorescence chemical combination of long wavelength's one sideThe molar absorption coefficient of the absorption band of thing is preferably 2000M^-1·cm^-1Above, more preferably5000M^-1·cm^-1Above.

The example with the compound of high like this molar absorption coefficient is two (3,5-dimethyl-2-Phenyl pyrazines) (the abbreviation: [Ir (mppr-Me) of (two valeryl methyls) iridium (III)₂(dpm)]，With reference to following Chemical formula 1), (acetylacetone,2,4-pentanedione root) two (4,6-diphenyl pyrimidine roots(diphenylpyrimidinato)) iridium (III) (abbreviation: [Ir (dppm)₂(acac)], referenceFollowing Chemical formula 2) etc. Especially, there is 5000M in use^-1·cm^-1Above molar absorptivity systemThe material of number is as [Ir (dppm)₂(acac) ,] time, can obtain the outside quantum that arrives 30% left and rightThe light-emitting component of efficiency.

[Chemical formula 1]

[Chemical formula 2]

N-shaped main body is to have pi-electron shortage type virtue heterocycle (π-electrondeficientHeteroaromaticring) compound represents. In other words, be the Constitution Elements as ringThere is the compound with hexa-atomic aromatic rings of the hetero atom (nitrogen or phosphorus etc.) that electronegativity is greater than carbon.For example, N-shaped main body can be the Benzoquinoxalines that has of acceptant electronics(benzoquinoxaline) any in the compound of skeleton (Benzoquinoxalines derivative),Such as 2-[3-(dibenzothiophenes-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation:2mDBTPDBq-II), 2-[4-(dibenzothiophenes-4-yl) phenyl] dibenzo [f, h] quinoxaline(abbreviation: 2DBTPDBq-II), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl) phenyl] dibenzo[f, h] quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophenes-4-yl) phenyl] two7mDBTPDBq-II) and 6-[3-(dibenzothiophenes-4-yl) (the abbreviation: of benzo [f, h] quinoxalinePhenyl] (the abbreviation: 6mDBTPDBq-II) of dibenzo [f, h] quinoxaline.

P-type main body is with aromatic amine (at least one aromatic rings is bonded to the compound of nitrogen-atoms) or clickZole derivatives represents. For example, p-type main body can be arbitrary in the compound in acceptant holeIndividual, " (9-phenyl-9H-carbazole-3-yl) triphenylamine (contracting such as 4,4 '-bis-(1-naphthyls)-4Write: PCBNBB), 4,4'-two [N-(1-naphthyl)-N-phenyl amino] biphenyl (abbreviation: NPBOr α-NPD) and 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl) triphenylamine (contractingWrite: PCBA1BP). Note, swash base again as long as the combination of N-shaped main body and p-type main body can formCompound, the present invention is not limited to these compounds.

Anodal 109 preferably use have high work function (concrete is more than 4.0eV) metal,Alloy, conductive compound and their mixture etc. Concrete example comprises indium oxide-oxygenThe oxidation that change tin (ITO:IndiumTinOxide, tin indium oxide), contains silicon or silicaIndium-tin oxide, indium oxide-zinc oxide, the indium oxide (IWZO) etc. that contains tungsten oxide and zinc oxide.These conducting metal oxides generally form by sputtering method, still, and also can be molten by usingThe formation such as glue-gel method.

For example, by sputtering method, use the oxidation that is added with 1wt% to 20wt% in indium oxideThe target of zinc, can form indium oxide-Zinc oxide film. By sputtering method, use in indium oxideBe added with the target of the tungsten oxide of 0.5wt% to 5wt% and the zinc oxide of 0.1wt% to 1wt%, canTo form IWZO film. Other examples be Graphene, gold, platinum, nickel, tungsten, chromium, molybdenum, iron,The nitride (such as titanium nitride) of cobalt, copper, palladium and metal material etc.

Note, when using described the answering below of organic compound and electron acceptor being mixed and formWhen condensation material forms the layer being included in light-emitting component 101 and form contiguously with positive pole, as useCan use metal, alloy, conductive compound and their mixture etc. in anodal material,And do not consider the size of work function; For example, also can use aluminium, silver or containing the alloy of aluminium (for exampleAl-Si) etc. Positive pole for example can be by shapes such as sputtering method or vapour deposition methods (comprising vacuum vapour deposition)Become.

Negative pole 108 preferably use have low work function (being preferably 3.8eV following) metal, alloy,The formation such as conductive compound and their mixture. Concrete example comprises and belongs to the periodic table of elementsIn the element of the 1st family and the 2nd family, alkali metal such as lithium and caesium, alkaline-earth metal such as calcium and strontium,Magnesium, their alloy (for example, Mg-Ag and Al-Li), rare earth metal such as europium and ytterbium andTheir alloy etc.

When using the described composite wood below organic compound and electron donor being mixed and formWhen material forms the layer being included in light-emitting component 101 and form contiguously with negative pole, can use eachKind of conductive material such as Al, Ag, ITO, the indium oxide-tin oxide that contains silicon or silica, and notConsider the size of work function. Note, in the time forming negative pole, can use vacuum vapour deposition or sputtering method.In the situation that using silver slurry etc., can adopt coating process or ink-jet method etc.

Fig. 3 B illustrates an example of the light-emitting device of present embodiment. Luminous dress shown in Fig. 3 BPutting is in the light-emitting device shown in Fig. 3 A, between light-emitting component 101 and negative pole 108, arrangesElectron injecting layer 113, and between light-emitting component 101 and anodal 109, hole injection layer is set114 light-emitting device.

In the time that electron injecting layer 113 and hole injection layer 114 are set, electronics and hole can be from negativeThe utmost point 108 and anodal 109 is injected in light-emitting component 101 efficiently, and can improve thus can dose-effectRate. At this, the laminated body of light-emitting component 101, electron injecting layer 113 and hole injection layer 114Be called as EL layer 110.

Hole injection layer 114 is the layers that comprise the material with high hole injection. As thering is heightThe material of hole injection, can use metal oxide, such as molybdenum oxide, titanium oxide, oxidationVanadium, rheium oxide, ruthenium-oxide, chromium oxide, zirconia, hafnium oxide, tantalum oxide, silver oxide, oxygenChange tungsten or manganese oxide. In addition, also can use phthalocyanine-like compound, such as phthalocyanine (abbreviation: H₂Pc)Or CuPc (II) (abbreviation: CuPc) etc.

Other examples of operable material are aromatic aminations of following low-molecular-weight organic compoundCompound etc., such as 4,4', 4 " tri-(N, N-diphenyl amino) triphenylamine (abbreviation: TDATA),4,4 ', 4 " tri-[N-(3-aminomethyl phenyl)-N-phenyl amino] triphenylamine (abbreviation: MTDATA),Two [N-(4-diphenyl amino the phenyl)-N-phenyl amino] biphenyl of 4,4'-(abbreviation: DPAB), 4,4'-Two (N-{4-[N'-(3-aminomethyl phenyl)-N'-phenyl amino] phenyl }-N-phenyl amino) biphenyl (contractingWrite: DNTPD), 1,3,5-tri-[N-(4-diphenyl amino phenyl)-N-phenyl amino] benzene (abbreviation:DPA3B), 3-[N-(9-phenyl carbazole-3-yl)-N-phenyl amino]-9-phenyl carbazole (abbreviation:PCzPCA1), 3, (the contracting of two [N-(9-phenyl carbazole-3-yl)-N-the phenyl amino]-9-phenyl carbazoles of 6-Write: PCzPCA2) and 3-[N-(1-naphthyl)-N-(9-phenyl carbazole-3-yl) amino]-9-phenyl clickAzoles (abbreviation: PCzPCN1).

Other examples that also have of operable material are that polymer (comprises that oligomer, dendroid are poly-Compound), PVK), poly-(4-vinyl triphenylamine) (contracting such as poly-(N-VCz) (abbreviation:Write: PVTPA), poly-[N-(4-{N'-[4-(4-diphenyl amino) phenyl] phenyl-N'-phenyl aminoPhenyl) Methacrylamide] PTPDMA), poly-[N, two (4-the butyl phenyl)-N of N'-, N'-(abbreviation:Two (phenyl) benzidine] Poly-TPD), be added with sour polymer, such as poly-(3,4-(abbreviation:Ethene dioxythiophene)/gather (styrene sulfonic acid) (PEDOT/PSS) and polyaniline/poly-(styrene sulphurAcid) (PAni/PSS).

As hole injection layer 114, can use organic compound and electron acceptor (acceptor)The composite being mixed to form. In organic compound, produce this multiple of hole by electron acceptorCondensation material has high hole injection and hole transport ability. In the case, organic compound is preferredFor (thering is the thing of high hole transporting at the material of excellent performance aspect the hole that produces of transmissionMatter).

The example that is used for the organic compound of composite can be various compounds, such as aromatic amineCompound, carbazole derivates, aromatic hydrocarbon and polymer (comprising oligomer, dendritic).Organic compound for composite is preferably the organic compound with high hole transporting, toolBody, is preferably and has 10^-6cm²The material of hole mobility more than/Vs. Note, exceptOutside these materials, can use any thing with the hole transport ability higher than electron-transportingMatter. Below, specifically describing can be for the organic compound of composite.

Can be aromatic amine compound for the example of the organic compound of composite, such asTDATA、MTDATA、DPAB、DNTPD、DPA3B、PCzPCA1、PCzPCA2、PCzPCN1、1,3,5-tri-(dibenzothiophenes-4-yl) benzene (abbreviation: DBT3P-II), 4, two [N-(the 1-naphthalenes of 4'-Base)-N-phenyl amino] biphenyl (abbreviation: NPB or α-NPD), N, two (the 3-methylbenzene of N'-Base)-N, TPD) and 4-phenyl N'-diphenyl-[1,1'-biphenyl]-the 4, (abbreviation: of 4'-diamines-4'-(9-phenyl fluorenes-9-yl) triphenylamine (abbreviation: BPAFLP) and carbazole derivates, such as4,4'-bis-(N-carbazyl) biphenyl (abbreviation: CBP), 1,3,5-tri-[4-(N-carbazyl) phenyl] benzeneTCPB), (abbreviation: of 9-[4-(N-carbazyl) phenyl-10-phenylanthracene CzPA), 9-benzene (abbreviation:Base-3-[4-(10-phenyl-9-anthryl) phenyl] and-9H-carbazole (abbreviation: PCzPA) and Isosorbide-5-Nitrae-bis-[4-(N-carbazyl) phenyl]-2,3,5,6-tetraphenyl benzene.

Other examples of operable organic compound are arene compounds, such as the 2-tert-butyl group-9,10-bis-(2-naphthyl) anthracene (abbreviation: t-BuDNA), the 2-tert-butyl group-9,10-bis-(1-naphthyl) anthracene,Two (3, the 5-diphenyl phenyl) anthracenes of 9,10-(abbreviation: DPPA), the 2-tert-butyl group-9, two (the 4-phenyl of 10-Phenyl) and anthracene (abbreviation: t-BuDBA), 9,10-bis-(2-naphthyl) anthracene (abbreviation: DNA), 9,10-bis-Phenylanthracene (abbreviation: DPAnth), 2-tert-butyl anthracene (abbreviation: t-BuAnth), 9, two (the 4-first of 10-Base-1-naphthyl) anthracene (abbreviation: DMNA), 9,10-two [2-(1-naphthyl) phenyl)]-2-tert-butyl anthracene,Two [2-(1-naphthyl) phenyl] anthracene and 2,3,6,7-tetramethyl-9 of 9,10-, 10-bis-(1-naphthyl) anthracene.

Other examples in addition of operable organic compound are arene compounds, such as2,3,6,7-tetramethyl-9,10-bis-(2-naphthyl) anthracene, 9,9'-dianthranide, 10,10'-diphenyl-9,9'-dianthranide, 10, two (the 2-phenyl)-9 of 10'-, 9'-dianthranide, 10,10'-is two[(2,3,4,5,6-pentaphene base) phenyl]-9,9'-dianthranide, anthracene, aphthacene, rubrene, perylene,2,5,8,11-tetra-(tert-butyl group) perylene, pentacene, coronene, 4,4'-two (2,2-diphenylacetylene)Biphenyl (abbreviation: DPVBi) and two [4-(2, the 2-diphenylacetylene) phenyl] anthracenes of 9,10-(abridge:DPVPA)。

Moreover the example of electron acceptor is organic compound, such as 7,7,8,8-four cyano-2, (the abbreviation: F of 3,5,6-tetrafluoro quinone bismethane₄-TCNQ), chloranil and belong to the periodic table of elementsThe oxide of the transition metal such as the metal of 48 families of family to the. Particularly, vanadium oxide, niobium oxide,Tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide and rheium oxide are preferred, because itThere is high electronics acceptance. Wherein, molybdenum oxide is especially preferred, because molybdenum oxide is at atmosphereIn stable, there is agent of low hygroscopicity, easily process.

Composite also can use above-mentioned electron acceptor and above-mentioned polymer such as PVK, PVTPA,PTPDMA or Poly-TPD form, and also can be for hole injection layer 114.

Electron injecting layer 113 is the layers that comprise the material with high electronic injection. Can be for electricityThe example of the material of sub-implanted layer 113 is alkali metal, alkaline-earth metal and their compound, such asLithium, caesium, calcium, lithium fluoride, cesium fluoride, calcirm-fluoride and lithia and rare earth compound,Such as fluoridizing erbium.

As electron injecting layer 113, also can use the material with high electron-transporting. HaveThe example of the material of high electron-transporting is that metal complex is such as Alq₃, three (4-methyl-8-hydroxylsQuinoline) aluminium (abbreviation: Almq₃), two (10-hydroxy benzo [h] quinoline) beryllium (abbreviation: BeBq₂)、BAlq、Zn(BOX)₂With (the abbreviation: Zn (BTZ) of two [2-(2-hydroxy phenyl) benzothiazole] zinc₂)。

Their other examples are heteroaromatics such as 2-(4-xenyl)-5-(4-tert-butyl groupsPhenyl)-l, 3,4-oxadiazole (abbreviation: PBD), 1,3-two [5-(to tert-butyl-phenyl)-1,3,4-Oxadiazole-2-yl] benzene (abbreviation: OXD-7), 3-(4-tert-butyl-phenyl)-4-phenyl-5-(4-Xenyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butyl-phenyl)-4-(4-secondBase phenyl)-5-(4-xenyl)-1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (contractingWrite: BPhen), BCP) and 4,4'-pair (5-Jia base benzoxazole-2-yls) two bathocuproine (abbreviation:Styrene (abbreviation: BzOs).

Also have other examples be polymer such as poly-(2,5-pyridine-bis-base) (abridge: PPy),Poly-[(9,9-dihexyl fluorenes-2,7-bis-bases)-copolymerization-(pyridine-3,5-bis-bases)] (abbreviation: PF-Py)With poly-[(9,9-dioctyl fluorene-2,7-bis-bases)-copolymerization-(2,2'-bipyridyl-6,6'-bis-bases)](abbreviation: PF-BPy). Material described herein is mainly to have 10^-6cm²Electronics more than/Vs movesMove the material of rate.

Note, except these materials, thering is appointing of the electron-transporting higher than hole transport abilityWhat material also can be for electron injecting layer 113. These materials with high electron-transporting also canFor described below electron transfer layer.

Or the composite that organic compound and electron donor (donor) are mixed to form is passableFor electron injecting layer 113. In organic compound, produce this multiple of electronics by electron donorCondensation material has high electronic injection and electron-transporting. At this, organic compound is preferably and is passingThe material of the aspect excellent performance of defeated produced electronics. Particularly, can use for electronicsIn the above-mentioned substance of transport layer any (as, metal complex and heteroaromatics).

As electron donor, can use the material that organic compound is shown to electron donability. ToolBody, preferred example is alkali metal, alkaline-earth metal and rare earth metal, such as lithium, caesium, magnesium,Calcium, erbium and ytterbium. Any one in alkali metal oxide and alkaline earth oxide is preferred,Its example is lithia, calcium oxide and barium monoxide etc., and can use lewis base as magnesia andOrganic compound is as tetrathiafulvalene (abbreviation: TTF).

Fig. 3 C illustrates an example of the light-emitting device of present embodiment. Luminous dress shown in Fig. 3 CPutting is in the light-emitting device shown in Fig. 3 B, light-emitting component 101 and electron injecting layer 113 itBetween electron transfer layer 111 is set, and establish between light-emitting component 101 and hole injection layer 114Put the light-emitting device of hole transmission layer 112.

As mentioned above, the N-shaped body layer 103 in light-emitting component 101 and p-type body layer 104 are alsoBe used separately as electron transfer layer and hole transmission layer. For electronics and hole are injected into efficiently and are sent outIn optical element 101, electron transfer layer 111 and hole transmission layer 112 are preferably set separately.

Electron transfer layer 111 is the layers that comprise the material with high electron-transporting. Pass as electronicsDefeated layer 111, can use the above-mentioned material with high electron-transporting. Electron transfer layer is not limited toIndividual layer can be the two-layer above lamination that comprises any one layer in above-mentioned substance.

Hole transmission layer 112 is the layers that comprise the material with high hole transporting. There is high holeThe example of the material of transporting is aromatic amine compound, such as NPB, TPD, BPAFLP, 4,4'-DFLDPBi) and 4,4'-(the abbreviation: of two [N-(9,9-dimethyl fluorene-2-yl)-N-phenyl amino] biphenyl(the abbreviation: BSPB) of two [N-(volution-9,9'-bis-fluorenes-2-yl)-N-phenyl amino] biphenyl. This instituteThe material of stating is mainly to have 10^-6cm²The material of hole mobility more than/Vs. Note, exceptOutside above-mentioned substance, there is the material of the hole transport ability higher than electron-transporting. Note, compriseThe layer with the material of high hole transporting is not limited to individual layer, can be two-layer above comprise above-mentionedThe lamination of any one layer in material.

As hole transmission layer 112, also can use carbazole derivates such as CBP, CzPA orPCzPA or anthracene derivant, such as t-BuDNA, DNA or DPAnth. As hole transmission layer112, also can use macromolecular compound such as PVK, PVTPA, PTPDMA or Poly-TPD.

Note above-mentioned hole injection layer 114, hole transmission layer 112, light-emitting component 101, electronicsTransport layer 111 and electron injecting layer 113 can by such as vapour deposition method (comprising vacuum vapour deposition),The method of ink-jet method or coating process and forming. Note, EL layer 110 not necessarily must comprise all onState layer.

As shown in Figure 3 D, also can anodal 109 and negative pole 108 between stacked multiple EL layer 110aAnd 110b. In the case, EL layer 110a and 110b at least comprise respectively sending out shown in Fig. 3 AThe EL layer 110 that optical element 101 or Fig. 3 B and Fig. 3 C are illustrated. At stacked EL layer 110aAnd between EL layer 110b, charge generating layer 115 is set. Charge generating layer 115 can use above-mentionedMaterial or the composite with high hole injection form. In addition, charge generating layer 115 canThe laminated construction of the layer that there is the layer that comprises composite and comprise other materials.

In the case, as the layer that comprises other materials, can use to comprise to there is electronics and giveProperty material and have high electron-transporting material layer, formed by nesa coating etc. layer.In addition, light-emitting component also can have that to obtain phosphorescence from a side EL layer luminous, and from the opposing partyEL layer obtain the structure of fluorescence radiation. Above-mentioned phosphorescence is luminous can be by adopting above-mentioned EL layerStructure obtains.

In addition, by making the glow color of EL layer different, can obtain from light-emitting device is overallTo the light of desirable color. For example, the glow color complementation of EL layer 110a and EL layer 110b,Therefore light-emitting device as a whole can transmitting white. Moreover same principle can be applied to be hadThe light-emitting device of three above EL layers.

Or, as shown in Fig. 3 E, also can between positive pole 109 and negative pole 108, form and compriseHole injection layer 114, hole transmission layer 112, light-emitting component 101, electron transfer layer 111, electricitySub-injecting layer 116, electronics relay layer 117 and be contacted with the composite layer of negative pole 108118 EL layer 110.

The composite layer 118 that is contacted with negative pole 108 is preferably set, in this case, can subtractsFew especially suffered damage of EL layer 110 in the time using sputtering method to form negative pole 108. Composite woodThe bed of material 118 can use the organic compound with high hole transporting to comprise the above-mentioned of acceptor materialComposite.

And, by electronic injection cushion 116 is set, can reduce composite layer 118 withInjection barrier between electron transfer layer 111; Be created in thus the electronics in composite layer 118Easily be injected in electron transfer layer 111.

As electronic injection cushion 116, can use the material with high electronic injection, allIf the compound of alkali metal, alkaline-earth metal, rare earth metal and above-mentioned metal is (as alkali metal chemical combinationThing (comprising that oxide such as lithia, halide, carbonate are such as lithium carbonate or cesium carbonate),Alkaline earth metal compound (comprising oxide, halide and carbonate) or rare earth compound (bagDraw together oxide, halide and carbonate).

Moreover, comprise and there is high electron-transporting and donor substance at electronic injection cushion 116In the situation of material, preferably add donor substance, so that donor substance is to having high electron-transportingThe mass ratio of material be 0.001:1 to 0.1:1. As the material with high electron-transporting,Can use the material same with above-mentioned electron transfer layer 111.

As donor substance, except the change of alkali metal, alkaline-earth metal, rare earth metal, above-mentioned metalCompound (as alkali metal compound (comprise oxide such as lithia, halide and carbonate such asLithium carbonate or cesium carbonate), alkaline earth metal compound (comprising oxide, halide and carbonate)And outside rare earth compound (comprising oxide, halide and carbonate), can useOrganic compounds such as four sulphur naphthonaphthalenes (tetrathianaphthacene) (abbreviation: TTN),Dicyclopentadienyl nickel or decamethyl dicyclopentadienyl nickel.

Moreover, preferably between electronic injection cushion 116 and composite layer 118, form electronicsRelay layer 117. Electronics relay layer 117 is not necessary to arrange; But, by tool is setHave the electronics relay layer 117 of high electron-transporting, electronics can be transferred to rapidly electronic injection bufferingLayer 116.

Electronics relay layer 117 is clipped between composite layer 118 and electronic injection cushion 116Structure is included in the acceptor material in composite layer 118 and is included in electronic injection cushionDonor substance in 116 is not easy to interact each other, and their function is not easy dry mutually thusThe structure of disturbing. Thereby, can prevent that driving voltage from increasing.

Electronics relay layer 117 comprises the material with high electron-transporting, and to there is high electronicsThe lumo energy of the material of transporting is arranged in the acceptor material that is included in composite layer 118Lumo energy be included in the material with high electron-transporting in electron transfer layer 111Mode between lumo energy forms.

In the time that electronics relay layer 117 comprises donor substance, the donor energy level of donor substance is also controlled and isBe arranged in the lumo energy of the acceptor material that is included in composite layer 118 and be included in electronics and passBetween the lumo energy of the material with high electron-transporting in defeated layer 111. As energy levelConcrete numerical value, is included in the LUMO of the material with high electron-transporting in electronics relay layer 117Energy level is preferably greater than or equal to-5.0eV, more preferably greater than or equal to-5.0eV and less than or equal to-3.0eV。

As the material with high electron-transporting being included in electronics relay layer 117, preferably makeWith phthalocyanine or there is the metal complex of metal-oxygen bonding and aromatic ligand.

As the phthalocyanine being included in electronics relay layer 117, particularly, preferably useCuPc, Tin Phthalocyanine (II) complex (Phthalocyaninetin(II) complex) (SnPc),Phthalocyanine Zn complex (Phthalocyaninezinccomplex) (ZnPc), Cobalt Phthalocyanine (II),β type (Cobalt(II) phthalocyanine, β-form) (CoPc), FePC(PhthalocyanineIron) (FePc) with 2,9,16,23-tetra-phenoxy groups-29H, 31H-Ranadylic phthalocyanine (Vanadyl2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine) any in (PhO-VOPc).

As the gold with metal-oxygen bonding and aromatic ligand being included in electronics relay layer 117Metal complex, preferably use has the metal complex of two keys of metal-oxygen. Two keys of metal-oxygenThere is acceptor's property (character of acceptant electronics); Therefore, electronics more easily shift (give andGive and accept). Moreover, can think that the metal complex of the two keys with metal-oxygen is stable.Thereby, there is the metal complex of two keys of metal-oxygen by use, can improve light-emitting deviceLife-span.

As the metal complex with metal-oxygen bonding and aromatic ligand, phthalocyanine is excellentChoosing. Particularly, vanadium oxygen phthalocyanine (Vanadylphthalocyanine) (VOPc), phthalocyanineTin oxide (IV) complex (Phthalocyaninetin (IV) oxidecomplex) (SnOPc)And phthalocyanine titanium oxide complex (PhthalocyaninetitaniumoxidecomplexEtc. (TiOPc) be preferred, because acceptor is high.

Note, as above-mentioned phthalocyanine, the phthalocyanine with phenoxy group is preferred.Particularly, having the phthalocyanine derivates of phenoxy group, is preferred such as PhO-VOPc. HaveThe phthalocyanine derivates of phenoxy group is easily dissolved in solvent, therefore, has easy to handle advantage and appearanceEasy-maintaining is for the advantage of the device of film forming.

Electronics relay layer 117 can also comprise donor substance. As donor substance, except alkali metal,The compound of alkaline-earth metal, rare earth metal, above-mentioned metal is (as alkali metal compound (comprises oxidationThing such as lithia, halide and carbonate are such as lithium carbonate or cesium carbonate), alkaline-earth metal chemical combinationThing (comprising oxide, halide and carbonate) and rare earth compound (comprise oxide,Halide and carbonate)) outside, can use organic compound such as four sulphur naphthonaphthalenesTTN), dicyclopentadienyl nickel or decamethyl dicyclopentadienyl nickel (tetrathianaphthacene) (abbreviation:.Be included in electronics relay layer 117 in these donor substance, electronics easily shifts and can be with lowVoltage drives light-emitting device.

In the situation that donor substance is included in electronics relay layer 117, pass as thering is high electronicsThe material of defeated property can use and have higher than being included in composite layer except above-mentioned substanceThe material of the lumo energy of the acceptor level of the acceptor material in 118. Particularly, preferably useHave greater than or equal to-5.0eV, more preferably greater than or equal to-5.0eV and less than or equal to-3.0eVThe material of lumo energy. As the example of this material, can Ju Chu perylene derivative, nitrogenousCondensed ring aromatic etc. Note, due to its high stability, nitrogenous condensed ring aromatic is preferredFor electronics relay layer 117.

The object lesson of perylene derivative be 3,4,9,10-perylenetetracarboxylic dianhydride (abbreviation: PTCDA),3,4,9,10-perylene tetracarboxylic acid bisbenzimidazole (abbreviation: PTCBI), N, N'-dioctyl-3,4,9,10-Perylene tetracarboxylic acid diimides (abbreviation: PTCDI-C8H) and N, N'-dihexyl-3,4,9,10-perylene four(the abbreviation: HexPTC) etc. of carboxylic acid imidodicarbonic diamide.

The object lesson of nitrogenous condensed ring aromatic is also [2,3-f] [1,10] phenanthroline of pyrazine-2,3-dimethoxy nitrile (abbreviation: PPDN), 2,3,6,7,10,11-six cyanogen-Isosorbide-5-Nitrae, 5,8,(the abbreviation: HAT (CN) of 9,12-, six azepine benzophenanthrenes₆), 2,3-diphenyl pyrido [2,3-b]Pyrazine (abbreviation: 2PYPR), 2, two (4-fluorophenyl) pyrido [2, the 3-b] pyrazines (contractings of 3-Write: F2PYPR) etc.

In addition, can use 7,7,8,8-tetracyano-p-quinodimethane (abbreviation: TCNQ), Isosorbide-5-Nitrae, 5,8-Naphthalene tetracarboxylic acid dianhydride (abbreviation: NTCDA), perfluor pentacene (perfluoropentacene),(the abbreviation: F of ten hexafluoro CuPcs₁₆CuPc), N, N'-is two(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-, 15 fluoro octyl groups)-Isosorbide-5-Nitrae, 5,8-naphthalene tetracarboxylic acidPyromellitic imide (abbreviation: NTCDI-C8F), 3', 4'-dibutyl-5,5 " bis-(dicyano AsiasMethyl) DCMT) and methylene richness the (abbreviation: of-5,5 " dihydro-2,2':5', 2 " tri-thiopheneStrangle alkene (for example, [6,6]-phenyl C₆₁Butyric acid methyl esters) etc.

Note, in the situation that donor substance is included in electronics relay layer 117, electronics relay layer117 can carry out shape by having the method such as the material of high electron-transporting and the common evaporation of donor substanceBecome.

Note, as mentioned above, the N-shaped body layer 103 in light-emitting component 101 and p-type body layer104 are used separately as electron transfer layer and hole transmission layer; Therefore, electronics not necessarily must be setOne or both in transport layer 111 and hole transmission layer 112. In the case, N-shaped main bodyLayer 103 is as electron transfer layer 111.

In above-mentioned light-emitting device, because being applied to the potential difference electric current stream between positive pole and negative poleCross, and because of at EL layer 110(or, 110a or 110b) in hole and electron recombination, thusLuminous. And this luminous either one or both of passing in anodal and negative pole is fetched to outside.Therefore, either one or both in positive pole and negative pole is the electrode with visible ray light transmission.

Note, hole blocking layer also can combine with light-emitting component 101.

By using the light-emitting device shown in present embodiment, can manufacture the luminous dress of passive-matrix typePut or by the active matric-type light-emitting device of the driving of transistor controls light-emitting device. In addition, luminousDevice should be applied to electronic equipment or lighting device etc.

Embodiment 3

In the present embodiment, to being used for manufacturing the illustrated light-emitting component 101a of embodiment 1Deng device and method describe. Manufacturing installation shown in Fig. 4 A is in vacuum processing chamber 201Comprise the first evaporation source 202, the second evaporation source 203 and the 3rd evaporation source 204. First to the 3rdEvaporation source 202 to 204 all has the peristome 223 of wire as shown in Figure 4 C like that, passes through resistanceMode of heating evaporates inner organic compound.

At this, the first evaporation source 202, the second evaporation source 203 and the 3rd evaporation source 204 make respectivelyN-shaped main body, object and the evaporation of p-type main body. The first to the 3rd evaporation source 202 to 204 also canBaffle plate is set respectively. Moreover the preferred temperature of controlling independently evaporation source, suitably controls thusThe vapour pressure of organic compound. For example, also the evaporation capacity of N-shaped main body can be set as to p-type master4 times of the evaporation capacity of body, and also the evaporation capacity of object can be set as to the evaporation capacity of p-type main body1%.

Moreover, for example, also can be with organic compound from the first evaporation source 202 and the 3rd evaporation source204 to compared with wide regional alignment and organic compound from the second evaporation source 203 to narrower regional alignmentThe peristome 223 of mode evaporation source has different shapes and size etc. Or, as Fig. 4 A instituteShow, the peristome 223 of evaporation source also can be orientated in different directions.

In vacuum processing chamber 201, can configure more than one substrate, two of preferred disposition withOn substrate (in Fig. 2 A, substrate 205 to 207), as shown, from left to right(in other words, in the direction substantially vertical with the direction of the peristome 223 of evaporation source) is with suitablySpeed move. Note, evaporation source also can be from different from the distance of substrate 205 to 207.

In the manufacturing installation shown in Fig. 4 A, in the part shown in 208, from the first evaporation sourceThe N-shaped main body major sedimentary of 202 evaporations. In the part shown in 209, from the first evaporation source 202Evaporation N-shaped main body, the object evaporating from the second evaporation source 203 and steam from the 3rd evaporation source 204The p-type main body of sending out deposits in certain proportion. Moreover, in the part shown in 210, from the 3rdThe p-type main body major sedimentary that evaporation source 204 evaporates.

Thereby, substrate 205 to 207 is during the left side moves to right, first form nType body layer 103, then, forms luminescent layer 102, then, forms p-type body layer 104. AsLight-emitting component 101b is such, between N-shaped body layer 103 and luminescent layer 102, forms N-shaped mistakeCross district 106, and form p-type transition region 107 between p-type body layer 104 and luminescent layer 102.In other cases, as light-emitting component 101c, luminescent layer and N-shaped body layer or p-type masterBetween body layer, do not form obvious border.

Manufacturing installation shown in Fig. 4 B is the dress obtaining by improving the manufacturing installation shown in Fig. 4 APut. In other words, manufacturing installation comprises the first evaporation source 212, second in vacuum processing chamber 211Evaporation source 213, the 3rd evaporation source 214, the 4th evaporation source 215 and the 5th evaporation source 216. At this,The first evaporation source 212 and the second evaporation source 213 make the evaporation of N-shaped main body; The 3rd evaporation source 214 makesObject evaporation, the 4th evaporation source 215 and the 5th evaporation source 216 make the evaporation of p-type main body.

The situation of manufacturing installation as shown in Figure 4 A, the peristome 223 of evaporation source can have notSame shape or size etc., can be different positions, also can in different directions, be orientated.In vacuum processing chamber 211, also can configure more than one substrate, preferred disposition is more than twoSubstrate (in Fig. 2 B, substrate 217 to 219), as shown, from left to right withSuitable speed moves.

In the manufacturing installation shown in Fig. 4 B, in the part shown in 220, from the first evaporation sourceThe N-shaped main body major sedimentary of 212 evaporations. In the part shown in 221, from the second evaporation source 213Evaporation N-shaped main body, the object evaporating from the 3rd evaporation source 214 and steam from the 4th evaporation source 215The p-type main body of sending out deposits in certain proportion. Moreover, in the part shown in 222, from the 5thThe p-type main body major sedimentary that evaporation source 216 evaporates.

As light-emitting component 101a, the manufacturing installation shown in Fig. 4 B can provide luminescent layer 102And between the interface between N-shaped body layer 103 and luminescent layer 102 and p-type body layer 104The change in concentration that interface is extremely acute.

Embodiment 4

In the present embodiment, can be used as N-shaped main body 2mDBTPDBq-II, can be used as p-type masterThe PCBNBB of body with and exciplex describe. Table 1 illustrate 2mDBTPDBq-II,PCBNBB the and at [Ir (dppm) that uses object suitable when these materials₂(acac)] and[Ir(mppr-Me)₂(dpm) main physics value].

[table 1]

Being mixed with in the region of 2mDBTPDBq-II and PCBNBB, lumo energy is-2.78eV,And HOMO energy level is-5.46eV. These energy levels respectively with 2mDBTPDBq-II and PCBNBB swashThe lumo energy of base complex and HOMO energy level equate. And, as object[Ir(mppr-Me)₂(dpm) lumo energy] and HOMO energy level are also equal energy levels.

On the other hand, [Ir (dppm)₂(acac) lumo energy] and HOMO energy level are all lower than above-mentionedEnergy level; Hence one can see that, [Ir (dppm)₂(acac)] easy trapped electron. This represents, is using[Ir(dppm)₂(acac) during] as object, with use [Ir (mppr-Me)₂(dpm)] compare, straightThe probability that connects recombination process is high.

In addition [the Ir (mppr-Me) in triplet excited state,₂] and [Ir (dppm) (dpm)₂(acac)]Energy level (T1 energy level) all than the energy of the 2mDBTPDBq-II in triplet excited state and PCBNBBMore than the low 0.1eV of level. Thus, [the Ir (mppr-Me) in triplet excited state₂(dpm)] and[Ir(dppm)₂(acac) state transitions] is to the triplet excited state of 2mDBTPDBq-II and PCBNBBProbability little. Especially, [Ir (dppm)₂(acac) more than the low 0.18eV of T1 energy level], this tableShow [Ir (dppm)₂(acac)] have higher than [Ir (mppr-Me)₂(dpm) luminous efficiency].

Fig. 5 A illustrates the molecular structure of 2mDBTPDBq-II. Generally speaking, at hetero atom (,There is the electronegative atom higher than carbon) import to the structure of the hexa-atomic aromatic rings such as phenyl ring such as nitrogen-atomsBecome the atomic time, hetero atom attracts the pi-electron on ring, and aromatic rings is easily in electron deficiency state.In the accompanying drawings, by dotted line around part A be equivalent to the part of pi-electron deficiency and this partEasily trapped electron. Generally speaking, comprise that the assorted aromatic of hexatomic ring is easily as N-shaped main body.

Fig. 5 B illustrates the molecular structure of PCBNBB. Generally speaking, be positioned at aromatic rings such as phenyl ringThe nitrogen-atoms in outside and ring key while closing, lone pair is fed to phenyl ring by nitrogen-atoms, thusElectronics becomes superfluous state and is easily released (, hole is easily captured). In the accompanying drawings, by voidLine around part B be equivalent to the part in rich pi-electron state, and this part is easily emitted electricitySon (or trapped hole). Generally speaking, aromatic amine compound easily becomes p-type main body.

Between 2mDBTPDBq-II and the LUMO of PCBNBB, there is larger difference, i.e. 0.47eV,And between HOMO, there are larger difference, i.e. 0.42eV. This difference is used as for electronics and holeStop, can prevent without compound carrier through luminescent layer. This height stopping is preferredMore than 0.3eV, more preferably more than 0.4eV.

By measuring luminescence generated by light, can determine whether N-shaped main body and p-type main body form sharp base multipleCompound. , can say when overlapping at the photoluminescence spectra of exciplex and the absorption spectrum of objectEnergy transfer process by Foster mechanism easily occurs.

Fig. 6 A and Fig. 6 B illustrate [Ir (dppm)₂(acac) UV, visible light of dichloromethane solution] is inhaledReceive spectrum (absorption spectrum 0). Be placed in silica dish at dichloromethane solution (0.093mmol/L)State under, use ultraviolet-uisible spectrophotometer (V550 is manufactured by Japan Spectroscopy Corporation),At room temperature absorbance spectrum.

In addition, Fig. 6 A and Fig. 6 B also illustrate the photoluminescence spectra of the film of 2mDBTPDBq-IIThe photoluminescence spectra (emission spectrum 2) of the film of (emission spectrum 1), PCBNBB andPhotoluminescence spectra (the emission spectrum of the film of the composite material of 2mDBTPDBq-II and PCBNBB3). 2mDBTPDBq-II in the film of composite material is 0.8:0.2 to the ratio of PCBNBB.

In Fig. 6 A, transverse axis represents wavelength (nm), and the longitudinal axis represents molar absorption coefficient ε（M^-1·cm^-1) and luminous intensity (arbitrary unit). In Fig. 6 B, transverse axis represents energy (eV),And the longitudinal axis represents molar absorption coefficient ε (M^-1·cm^-1) and luminous intensity (arbitrary unit).

From the absorption spectrum 0 of Fig. 6 A, [Ir (dppm)₂(acac)] near 520nm, haveBroad absorption band. This absorption band can think contribute to very much luminous.

Compare with 2 with emission spectrum 1, the peak value of emission spectrum 3 is positioned at long wavelength (low-yield)One side. And, to compare with 2 peak value with emission spectrum 1, the peak value of emission spectrum 3 is bordering on[Ir(dppm)₂(acac) absorption band]. Particularly, [Ir (dppm)₂(acac) absorption light]Difference between peak value and the peak value of emission spectrum 3 of spectrum 0 is 0.02eV.

Known, compared with the emission spectrum of organic compound monomer, 2mDBTPDBq-II and PCBNBBThe peak value of emission spectrum of composite material be positioned at long wavelength (low-yield) side. It is from then on known,By mixing 2mDBTPDBq-II and PCBNBB, form exciplex. In addition, do not observeTo the emission spectrum that derives from 2mDBTPDBq-II or PCBNBB monomer, this means2mDBTPDBq-II and PCBNBB excite respectively, also form at once exciplex.

The peak value of the emission spectrum of composite material has and [Ir (dppm)₂(acac) absorption spectrum]Thinking in 0 contributes to the larger overlapping of luminous absorption band very much. This represents, comprises2mDBTPDBq-II, PCBNBB and [Ir (dppm)₂(acac) light-emitting component] has from swashing base multipleThe higher efficiency that compound shifts to the energy of guest molecule.

Embodiment 1

In the present embodiment, manufacture the light-emitting component of a mode of the present invention, and its characteristic is enteredRow is evaluated. In the light-emitting component of the present embodiment, use 2DBTPDBq-II as N-shaped main body,Use PCBA1BP as p-type main body.

In the present embodiment manufacture light-emitting component have from upper towards substrate with negative pole, electronic injectionLayer, electron transfer layer, ground floor (N-shaped body layer), luminescent layer (have N-shaped main body and pThe layer of type main body), the second layer (p-type body layer), hole injection layer, anodal sequential cascadeLayer structure.

Comprise above-mentioned material, the chemical formula (structure of the material using in the present embodiment is below shownFormula). Note, omit the chemical formula of the material having illustrated.

The manufacture method of the light-emitting component of the present embodiment is below shown. First, logical in glass substrateCross the indium tin oxide target (ITSO) that sputtering method forms silicon oxide-containing, form thus anodal. Note, by itThickness is set as 110nm, and its electrode area is set as to 2mm × 2mm.

Then, as the pretreatment in order to form light-emitting component on substrate, surperficial at waterWashing and at 200 DEG C, carry out the roasting of 1 hour after, carry out UV ozone treatment 370 seconds. SoAfter, being put into pressure, substrate is lowered to 10^-4In the vacuum deposition apparatus of Pa left and right, andIn the heating clamber of vacuum deposition apparatus, carry out the vacuum baking of 30 minutes with 170 DEG C, then to liningCooling about 30 minutes carries out at the end.

Then, solid by being provided with anodal substrate to be provided with anodal surface mode downwardFix on the substrate support in vacuum deposition apparatus. Then, 10^-4Under the decompression of Pa left and right, steam altogetherPlating DBT3P-II and molybdenum oxide (VI), thus hole injection layer on positive pole, formed. By holeThe thickness of implanted layer is set as 40nm, and DBT3P-II is adjusted to the weight ratio of molybdenum oxide4:2 (=DBT3P-II: molybdenum oxide).

Then, on hole injection layer, by vapour deposition method form thickness be 20nm by PCBA1BPThe second layer forming.

Moreover, evaporation PCBA1BP, 2DBTPDBq-II, [Ir (dppm) altogether₂(acac)] come theTwo layers of upper luminescent layer that forms. At this, 2DBTPDBq-II is to PCBA1BP and [Ir (dppm)₂(acac)]Weight ratio be adjusted to 0.8:0.2:0.05. The thickness of luminescent layer is set as to 40nm.

And, on luminescent layer, form by vapour deposition method the 2DBTPDBq-II that thickness is 10nmFilm, forms ground floor.

Then, on ground floor, to form thickness be 20nm bathophenanthroline (abbreviation: BPhen) film,Form electron transfer layer.

And, on electron transfer layer, form the lithium fluoride that thickness is 1nm (LiF) by vapour deposition methodFilm, forms electron injecting layer.

Finally, as negative pole, form by vapour deposition method the aluminium film that thickness is 200nm. Thus, systemMake light-emitting component. Note, in above-mentioned evaporation step, all carry out evaporation by resistance heated method.Table 2 illustrates the component structure of the light-emitting component obtaining by above-mentioned steps.

[table 2]

[table 2] (connecting table)

In the glove box that comprises blanket of nitrogen, not to be exposed to the mode sealed light emitting unit of atmospherePart. Then, measure the operating characteristic of light-emitting component. Note, at room temperature (be held in 25 DEG CAtmosphere in) measure.

Fig. 7 A illustrates the current density dependence of the brightness of obtained light-emitting component, and Fig. 7 B illustratesThe voltage-dependent of brightness, and Fig. 7 C illustrates the brightness dependence of current efficiency. Table 3 illustrates instituteThe key property of the light-emitting component obtaining. In order to obtain 1000cd/m²The brightness of left and right is neededVoltage pole low (2.6V). The light-emitting component obtaining has more than 70% power efficiency and is heightEfficiency.

[table 3]

[table 3] (connecting table)

Embodiment 2

In the present embodiment, manufacture the light-emitting component of a mode of the present invention, and measure that this is luminousElement. In the present embodiment, use 2mDBTPDBq-II as N-shaped main body, as p-type main bodyUse PCBA1BP, manufacture light-emitting component.

The light-emitting component of manufacturing in the present embodiment has the layer identical with the light-emitting component of embodiment 1Structure. Use the material having illustrated. Moreover, except N-shaped main body difference, manufacture methodIt is identical with embodiment 1 that (in other words, use 2mDBTPDBq-II replaces embodiment's 12DBTPDBq-II); Thus, omit detailed content. Note, 2mDBTPDBq-II is below shownStructure.

Table 4 illustrates the component structure of obtained light-emitting component.

[table 4]

[table 4] (connecting table)

Fig. 8 A illustrates the current density dependence of the brightness of obtained light-emitting component, and Fig. 8 B illustratesThe voltage-dependent of brightness, and Fig. 8 C illustrates the brightness dependence of current efficiency. Table 5 illustrates instituteThe key property of the light-emitting component obtaining. In order to obtain 1000cd/m²The brightness of left and right is neededVoltage pole low (2.7V). The light-emitting component obtaining have more than 25% external quantum efficiency andFor high efficiency. Known existing light-emitting component results from light and takes out the upper of efficiency and external quantum efficiencyBe limited to 20% left and right. But, by using the concept of GCCH, can realize having and exceed 25%The formation of light-emitting component of external quantum efficiency.

[table 5]

[table 5] (connecting table)

Description of reference numerals

101: light-emitting component; 101a: light-emitting component; 101b: light-emitting component; 101c: luminousElement; 102: luminescent layer; 103:n type body layer; 104:p type body layer; 105: objectMolecule; 106:n type transition region; 107:p type transition region; 108: negative pole; 109: positive pole;110:EL layer; 110a:EL layer; 110b:EL layer; 111: electron transfer layer; 112: holeTransport layer; 113: electron injecting layer; 114: hole injection layer; 115: charge generating layer; 116:Electronic injection cushion; 117: electronics relay layer; 118: composite layer; 201: vacuum placeReason chamber; 202: the first evaporation sources; 203: the second evaporation sources; 204: the three evaporation sources; 205:Substrate; 206: substrate; 207: substrate; 211: vacuum processing chamber; 212: the first evaporation sources;213: the second evaporation sources; 214: the three evaporation sources; 215: the four evaporation sources; Steaming in 216: the fiveRise; 217: substrate; 218: substrate; 219: substrate; 223: peristome

The application is submitted to the Japanese patent application of Japan Office based on March 30th, 2011No.2011-074272, is incorporated in this by its complete content by reference.

Claims (25)

1. a light-emitting component, comprising:

The first electrode;

Hole injection layer on described the first electrode;

Ground floor on described hole injection layer, this ground floor comprises its hole transport ability ratioThe first organic compound that its electron-transporting is high;

Luminescent layer on described ground floor, this luminescent layer comprises phosphorescent compound, describedOne organic compound with and electron-transporting than high second organic of its hole transport abilityCompound;

The second layer on described luminescent layer, this second layer comprises described the second organic compound;

Electron injecting layer on the described second layer; And

The second electrode on described electron injecting layer,

Wherein, select described the first organic compound and described the second organic compound, withJust form betwixt exciplex, and

Wherein, described phosphorescent compound is organometallic complex, and this organic metal coordinatesThing come from absorption and described exciplex luminous overlapping that triplet MLCT shifts.

2. light-emitting component according to claim 1, wherein, described phosphorescence chemical combinationThing comprises iridium.

3. light-emitting component according to claim 1, wherein, described first organicCompound is aromatic amine or carbazole derivates.

4. light-emitting component according to claim 1, wherein, described second organicCompound has pi-electron shortage type virtue heterocycle.

5. light-emitting component according to claim 4, wherein, described pi-electron lacksType virtue heterocycle is to have its electronegativity to be greater than the element of carbon as the Constitution Elements of described ringHexatomic ring.

6. light-emitting component according to claim 4, wherein, described pi-electron lacksType virtue heterocycle is Benzoquinoxalines.

7. light-emitting component according to claim 1, also comprises described the second electrodeAnd the electron transfer layer between the described second layer.

8. light-emitting component according to claim 1,

Wherein, described ground floor also comprises described the second organic compound, and

Wherein, in described ground floor, from described the first electrode to described luminescent layerThe change in concentration of the above the second organic compound of direction.

9. light-emitting component according to claim 1,

Wherein, the described second layer also comprises described the first organic compound, and

Wherein, in the described second layer, from described the second electrode to described luminescent layerThe change in concentration of the above the first organic compound of direction.

10. light-emitting component according to claim 1, wherein, at described luminescent layerIn, at the above first organic compound of the direction from described ground floor to the described second layerConcentration and the change in concentration of described the second organic compound.

11. one kind comprises the electronic equipment of light-emitting component according to claim 1.

12. one kind comprises the lighting device of light-emitting component according to claim 1.

13. 1 kinds of light-emitting components, comprising:

The first electrode;

An EL layer on described the first electrode;

Charge generating layer on a described EL layer;

The 2nd EL layer on described charge generating layer; And

The second electrode on described the 2nd EL layer,

Wherein, at least one in a described EL layer and described the 2nd EL layer comprises:

Comprise the first organic compound that its hole transport ability is higher than its electron-transportingGround floor;

Comprise the second organic compound that its electron-transporting is higher than its hole transport abilityThe second layer; And

Be clipped in the luminescent layer between described ground floor and the described second layer, this luminescent layer comprisesPhosphorescent compound, described the first organic compound and described the second organic compound,

Wherein, select described the first organic compound and described the second organic compound, withJust form betwixt exciplex, and

Wherein, described phosphorescent compound is organometallic complex, and this organic metal coordinatesThing come from absorption and described exciplex luminous overlapping that triplet MLCT shifts.

14. light-emitting components according to claim 13, wherein, described phosphorescenceCompound comprises iridium.

15. light-emitting components according to claim 13, wherein, described first hasOrganic compounds is aromatic amine or carbazole derivates.

16. light-emitting components according to claim 13, wherein, described second hasOrganic compounds has pi-electron shortage type virtue heterocycle.

17. light-emitting components according to claim 16, wherein, described pi-electron lacksWeary type virtue heterocycle is to have its electronegativity to be greater than the element of carbon as the formation unit of described ringThe hexatomic ring of element.

18. light-emitting components according to claim 16, wherein, described pi-electron lacksWeary type virtue heterocycle is Benzoquinoxalines.

19. light-emitting components according to claim 13, wherein, a described ELAnother emitting fluorescence in layer and described the 2nd EL layer.

20. light-emitting components according to claim 13, wherein, a described ELAnother transmitting phosphorescence in layer and described the 2nd EL layer.

21. light-emitting components according to claim 13,

Wherein, described ground floor also comprises described the second organic compound, and

Wherein, in described ground floor, from described the first electrode to described luminescent layerThe change in concentration of the above the second organic compound of direction.

22. light-emitting components according to claim 13,

Wherein, the described second layer also comprises described the first organic compound, and

Wherein, in the described second layer, from described the second electrode to described luminescent layerThe change in concentration of the above the first organic compound of direction.

23. light-emitting components according to claim 13, wherein, described luminousIn layer, at the above first organic compound of the direction from described ground floor to the described second layerThe change in concentration of the concentration of thing and described the second organic compound.

24. 1 kinds comprise the electronic equipment of light-emitting component according to claim 13.

25. 1 kinds comprise the lighting device of light-emitting component according to claim 13.